Basically, it’s a de-Christianized form of right wingery that is drinking deep of white supremacy and racialism. Sometimes, it appeals to something called “Western” Christianity, but this is basically a fig leaf for getting discernment-free conservatives to jettison actual Christian teaching in favor of nutty white supremacy by rhetoric about how Euro-superiority makes it plain that the whole “in Christ there is neither Jew nor Greek” race indifference is a huge mistake.
Other times, it daubs on a layer of pseudo-science by tossing around the phrase “human biodiversity” (by which they mean “some races are inferior to others”).
And not infrequently, some of its adherents ditch so much as the figleaf of Christianity (since Christianity really is irreconcilable with racism) and openly promotes bullshit “northern” neo-paganism as they get in touch with their inner Himmlers. Because everybody knows that the people who erected standing stones as their highest achievement were just about to usher in a golden age when they were rudely interrupted by brown ruffians named Augustine and St. Paul and Plato who tamed their manly Nordic creativity with their ethnically impure southern barbarism.
As socially maladjusted jerks always do, they trumpet their moral repulsiveness as a mark of “courage” and declare anybody who holds to actual Christian beliefs about the moral evils of racism are part of something called “The Cathedral” (an amorphous bogeyman compact of designated enemies critical of racialism). Discernment-free conservatives who react Pavlovianly to embrace anything that is “anti-PC” can be easily snookered by this tactic, which is why the movement is growing, almost exclusively among righties.
A conservatism decoupled from the Christian tradition will not be a good thing any more than liberalism decoupled from the Faith has been. A conservatism that perverts the Christian tradition into the service of racialism and white supremacy will be a deeply evil thing. Only a race as fallen and stupid as homo sapiens can look back on the 20th century and conclude, “Racial ideology is absolutely the way to go!” But to step from the Catholic faith into the sewer of racialism take a special kind of stupid.